Safer nuclear reactor with combined water coolant and moderator

摘要

A water-cooled and moderated nuclear reactor is claimed, where the core (4) has a height to diameter ratio of at least 1.5:1. The core (4) is surrounded by a gap (3, 5) which is filled with water and functions as a reflector. The fuel elements are block shaped made from ceramic material and have coolant channels within them. The fuel itself within the elements is in the form of coated particles. A water inlet device (21a) to the reactor has valves which are designed to lower the reactor pressure when it rises too high by letting out water. Arranged around the reflector water gap (3, 5) is a layer (6) of high neutron absorption capacity.